112 
OTIS F. CURTIS 
Table 9. Crataegus sp. April to May 18, IQIQ 
X. Check, not ringed. 
A. Ringed at the second internode below the terminal bud. 
B. Ringed at the fourth internode below the terminal bud. 
C. Ringed at the seventh or eighth internode below the terminal bud. 
All lateral buds were removed in each case. 
X 
A 
B 
c 
No, 
Length in 
Number of 
Length in 
Number of 
Length in 
Number of 
Length in 
Number of 
Mm. 
Leaves 
Mm. 
Leaves 
Mm. 
Leaves 
Mm. 
Leaves 
I 
65 
5 
0 
0 
dried 
8. 
3 
2 
70 
7 
7 
(green 
15 
2 
35 
4 
only 
3 
85 
8 
0 
15 
3 
30 
4 
45 
4 
(a) I 
(green 
10^ 
I 
35 
3 
{h) 0 
only) 
5 
40 
5 
dried 
20 
(green 
35 
4 
only) 
6 
35 
8 
6 
(green 
15 
(green 
ID 
green 
only) 
only) 
7........ 
70 
(a) 6 
(green 
12 
(green 
20 
(6) 30^ 
only) 
only) 
8 
(a) 55 
5 
0 
dried 
0 
30 
2 
{b) 50 
5 
60^ 
dead 
Ave 
57-2 
6.2 
2.2 
0 
II. 0 
0.5 
25.4 
2.7 
Starch tests: 
X. Starch fairly abundant in primary xylem, pith, medullary rays, and outer cortex» 
both near the tip and near the base. In nos. 2, 3, 4, 7, 80, and 8&, cambial growth 
was started and starch had largely disappeared from the outer part of the medullary 
rays. 
A. No trace of starch above rings except in no. 5 which contained traces in the pith- 
Below rings just as in checks. Nos. 4, 6, and 7 tested for starch in region of ring 
showed none in upper part, traces in middle, similar to check in lower part. 
B. No traces of starch above rings, except in nos. I and 8 which had evidently died early. 
Below rings just as in checks. Nos. 5, 6, and 7 tested for starch in region of ring 
showed none in upper part, while the lower part appeared about the same as just 
below the ring.^ 
C. No starch above the rings, except in no. 6 in which the terminal bud had been broken 
off and adventitious buds were just starting. In three cases there were slight traces 
in 2-3 pith cells. Below rings starch was fairly abundant as in the check stems. 
In each case in which growth had ceased, the starch above the ring had 
disappeared. If something other than sugar were the limiting factor, one 
would expect that the starch could not be utilized, yet the shorter the piece 
above the ring the more rapid was the disappearance of the starch and the 
earlier the cessation of growth. In a few exceptions with Crataegus and 
Acer a very short piece above a ring sometimes died before all the starch 
^ In these twigs a narrow strip of phloem was left covering less than one fourth of the 
circumference. 
^ In no. 4 a narrow strip of phloem had healed over under the paraffin. Starch was 
fairly abundant in primary xylem, pith, and medullary rays. None in cortex. Below ring 
same as in checks. 
